In exercising the powers provided for in this chapter, the Authority shall comply with the obligations arising from international treaties to which the Kingdom is a party and the provisions of legislation regulating air and maritime traffic and meteorology. Article (49) Preventing Harmful Interference with Radio-communications No Person shall unlawfully use any Telecommunications Equipment for the purpose of causing harmful interference with any communications or continue to cause such harmful interference after receipt of an order from the Authority to cease such interference unless such interference is caused by force majeure or emergency or rescue operations. Article (50) Obligations of a Frequency Licensee Without prejudice to any condition contained in any Frequency License: 1) The operation of a Telecommunications Network that uses radio frequency spectrum is the sole responsibility of the relevant Licensee. 2) The Frequency License holder and its employees and agents may not use a secret sign or code in messages and conversations over the Telecommunications Network in contravention of the provisions of this Law and the regulations issued for the enforcement of this Law. Article (51) Modification and Revocation of a Frequency License a) Subject to the provisions provided for in Article (34) of the Law, the Authority may modify the conditions of a Frequency License. b) The Authority shall have the right to revoke a Frequency License before the expiry of its term in any of the following cases: 1) The Licensee consents to the revocation.